I don’t watch any television.
I’m not quite in the ‘any amount is too much’ camp, but I’d say that any amount could be too much, and even mild viewing isn’t great for you. There are some programs that might even be beneficial, but the medium itself certainly isn’t the best way of gaining information. The other 99% of programming on television is mindless crap.
I’m not 100% sure about this, but I think I remember reading that about 50% of Americans say they watch “too much” television. If you think you watch too much, then you do.
Assuming you work 8 hours daily, and sleep 8 hours daily, if you spend even two hours watching television every day, that’s a significant amount of your leisure time devoted to staring at a screen absorbing advertisements and other people’s ideas without much (if any) interaction with the ideas being put forth by the medium. (Ideas that tens of thousands of other people are absorbing as well, something that I find unsettling, and the reason I stopped watching television two years ago this month.) Television viewing is a passive activity, and a one-way channel, with the television programming influencing you without your influencing the programming. I see that as a bad thing.
I don’t think computer use is as bad as television watching, but I think both have negative consequences. And I use the computer way too much.